[ Texturing ] Techniques for adding general and specific dirt to a texture

rares

Hy guys ! i was wondering what tricks/techniques do you use for adding dirt/grime etc. to your textures. The one i use right now is not really working for me in terms of realism(i use a layer filled with a dirt texture and use a soft brush to paint in the mask). Any suggestions, links to tutorials or any information on the matter is apreciated

r_fletch_r

You need to study what you are texturing. Dirt and grime tend to build up/get scratched off from certain areas depending on the purpose of the object. Generally crevices tend to collect dirt so for a first pass you can create an ambient occlusion map as a mask.

Generally Its down to good reference and observation. Find Pictures of wear and dirt and deconstruct them. Try to understand why certain areas are dirty. Are they scratched and rusty. is water running down them and cleaning the dirt of but causing rust. Are there moving parts removing the dirt. Is the are near a wheel and having dirt sprayed onto it?

A nice way to apply dirt can be photoshop brushes. If you find a nice picture of dirt its a good idea to save it and turn it into a brush you can use later.
http://www.bittbox.com/photoshop/how-to-make-a-photoshop-brush
used carefully you can get some really realistic effect quickly with a good dirt brush.

Mr. Bean

http://features.cgsociety.org/story_custom.php?story_id=4678

Tips #6 and #7 should especially help, but they're all good. Make sure you look at the second page.

rares

thanks guys! keep the tips coming, i need every ounce of info i can get

Racer445

For dirt the first thing I do is duplicate the AO, then I use Hue/Saturation on Colorize mode to make the shadows a orange/brown. The layer is kept on Normal but the Blend If options are changed so there is barely any white left showing. On the mask I then take a photo of fine grained dirt, desaturate it, and play with the contrast, as well as use cloudy brushes to remove dirt from certain areas.

I generally try to stay away from hand painting dirt in most cases. It's very time consuming.

divi

baking light from different directions can also be neat to get masks for deposits and bleached areas.

snow

racer445 i'm always stalking your tips and tricks, i love you man

BradMyers82

Mr. Bean: I never knew that about hold "Alt" during blend if to get smooth results. It appears it splits the arrow in half and you have extra control there. This is a HUGE trick that I didn't know about. Thanks for posting that tutorial man!

Racer445: Really solid advice as always, Thanks! Using the AO as a base to get dirt in the right areas is a really smart idea, can't wait to try it out!